Emily is 4 times as old as Vanessa and is also 12 years older than Vanessa. How old is Vanessa?
Explanation: We can use the given information to write down two equations that describe the ages of Emily and Vanessa. Let Emily's current age be $e$ and Vanessa's current age be $v$ $e = 4v$ $e = v + 12$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $v$ , and both of our equations have $e$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $4v$ $-$ $ (v + 12)$ which combines the information about $v$ from both of our original equations. Solving for $v$ , we get: $3 v = 12$ $v = 4$.